Hi there,
I have a '72 FLH with stock exhaust (dual w/crossover), and have been looking around at swap meets for a decent set of drag pipes. I know about drag pipes reducing performance, etc., I just like the look and sound. So one night I was riding home, and about 6 miles from home, my left muffler fell off. The clamp that holds it to the headpipe had worked its way backward on the muffler, and the clamp that holds the muffler to the bracket had broken. It was dark, but thankfully the muffler landed on the shoulder, so I found it pretty quickly. Rode to work the next day with just the right side muffler and thought to myself, 'self, this bike has a nice growl'. So I went home and took the other muffler off. Messed with the carb to get the fuel/air mixture right, and have been running it with just the open headpipes for the past few weeks. Seems to be running okay, but should I worry about it hurting anything? I've noticed I've lost quite a bit of power in the higher RPMs (which seems strange to me since the exhaust is flowing more freely), and it sometimes won't do more than 70mph... gonna mess with the carb again tonight, but if I can't get it sorted out, I'm going to just put the mufflers back on (or at least one of them).
Thanks for reading that long *** story for such a silly, simple question...
Thanks, -Danny

 

my guess is that its running lean and you need to do rejetting in order to get it running right. Beautiful bike

 

I rejetted shortly before the muffler fell off, I'm running a .295 intermediate and a 72 main (carb is an S&S Super E). Should I bump each of them up a size? And thank you, I love it. Couldn't dream of a better first bike.

 

Judging by the blue pipes you are running lean or your timing is off.

 

I would run a least some type of muffler on a bike like that, preferably period correct, but that's just me. Regardless what you decide that's a beautiful machine. Treat her well.

 

Pipes were blue when I got it. Though it was my understanding that pipes blue from it running too rich and causing the fuel to burn in the exhaust. Timing could possibly be off.

 

I ended up putting the right side muffler back on and retuned the carburetor. Already runs much better. just too quiet. I believe they're the original mufflers, otherwise I might mess with the baffle...

 

Jetting is the key. My '76 will get way above 70 mph

 

Yeah, I've hit 85 or so with the mufflers. I'm looking at a set of drag pipes this weekend, if I get them, I'll be rejetting.

 

While the bike will run with drags you'll be some losing power just where in the range depends on how fat you jet it , you gotta have some back pressure to carberate right. The make torque cones that look a big washer with a bolt on the side to install just inside the outlet of the pipes and you tune by turning the washer a bit at a time till you find the sweet spot. Still makes lots of racket just takes the edge of it, the carb tunes easier, plugs will last longer, the pipes won't blue or yellow out half the length if you get it right and helps gas mileage.